YR 8 Topic 2. Forces Select the online test

Key Concepts	Vocab	More Vocab
A force is a push or a pull. Simple machines use less force or change the direction of a force. Levers are force multipliers or speed multipliers Mechanical advantage is the load divided by the effort. (or the distance of the effort from the fulcrum divided y the distance of the load from the fulcrum) A wheel is a bent lever that rotates around the axle (fulcrum) Gears are a special kind of wheel Pulleys can be used to reduce the effort required to lift a load. We can calculate work and Mechanical advantage	Simple machines Ramp Lever Inclined plane Screw Force Effort Load Work = force X distance Mechanical advantage = Load / Effort	Pulley wheel torque gear Lever fulcrum teeth
Concepts	Suggested activity	Extension activity
8.1 Simple Machines A force is a push or a pull. Simple machines use less force or change the direction of a force. Calculate work and mechanical advantage.	Watch this video and list all the simple machines http://oxleylearning.org/science/2008/02/29/simple-machines/ Simple machine examples Practical 8.1 p 245 Questions 1 to 17 Hmwk book 8.1 For some movies and games go here Machine videos - there are games and quizes and a number of videos here - be sure to scroll down the page. Try this site for a simple explanation of simple machines http://www.edheads.org/activities/simple-machines/index.shtml >	Ques 17 to 27 Science at work p 244 try this simple machines song http://www.youtube.com/watch?v=l1Fhs8pXGxM&feature=related
8.2 Levers Levers are force multipliers (Class 1 and 2) Correctly use terms fulcrum, effort, load Levers are speed multipliers (Class 3) Calculate Mechanical advantage and work done	Use a variety of levers and draw them to show the effort and load and fulcrum View this site and make some notes http://edhelper.com/SimpleMachines.htm Draw and label examples of a Class 1 lever, a Class 2 lever and a Class 3 lever. p249 Q 1 to 10 p250 Q 17 to 19 do at least 2 of the following pracs Prac 1 -p251 Prac 2 - p252 Prac 3 - p253 Hmwk - 8.2	Surfing - p257 Constructing p 257 Watch this tv add using levers
8.3 Wheels axles and gears Wheels and axles Gears Calculate Mechanical advantage and work done	Construct a table to compare Wheels as force multipliers and Speed multipliers include examples of each (p258 to 259) Draw and label a gear system - see p260 Play with the Lego gears - new equip available, mouse trap racer, or cotton reel racer Write a paragraph on how Gears can be used as a force multiplier or a speed multiplier Questions p 261- 1 to 10 and Q17 and 18 Hmwk 8.4	• Use the STELR Windmills to explore gearing and power output • Hmwk 8.5
8.4. Pulleys Single pulleys change direction of a force Multiple pulleys use a small effort to lift a large load Calculate Mechanical advantage and work done	Draw examples of single pulley systems and label the effort and load Draw examples of a multiple pulley system and label the effort and the load Prac 1 p 268 Prac 2 p 269 Use the formula Work = effort force X the distance moved to calculate the work done in Prac 2 - how does this compare to the results gained fro the prac. p267 Ques 1 to 10 and Q 14 and 16 Hmwk 8.6 and 8.7	More on Prac 2 - What are Newtons and why are they used in this topic? Prac 3 - p270 Prac 4 - p271
Putting it all together Use the things you have learnt - This is an assessment task	Simple machine quiz Video of simple machines Watch these complicated machines: http://mytechnologyworld9.blogspot.com.au/2010/08/complicated-mechanisms-explained-in.html Practical exam: Look at the box of kitchen utensils and tools - Construct a table to classify the items in terms of what type of machine it is and whether it multiplies speed or force. Use formula to calculate the work and mechanical advantage of one item. Construction Assessment: Using the ideas you have learnt create/build a machine that combines 2 or more simple machines. Use any of the following to Build our creation paddle popstick, toothpicks, skewers string and some glue or sticky tape
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Online test	Online test Instructions you will be asked to enter your first name and last name put your class in front of your first name (in the first field or type box) Eg 8H Sarah put your last name in the second field Eg Smith put this access code in the third field 3LMU click this link to get to the online test http://www.classroomclipboard.com/490625/Home/Test/091a4d31229719d28ceaea02d65eb563#/Finished.xaml